/* libppm1.c - ppm utility library part 1
**
** Copyright (C) 1989 by Jef Poskanzer.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation.  This software is provided "as is" without express or
** implied warranty.
*/

#include <string.h>
#include <stdio.h>
#include <errno.h>
#include "ppm.h"
#include "libppm.h"
#include "pgm.h"
#include "libpgm.h"
#include "pbm.h"
#include "libpbm.h"

void
ppm_init( argcP, argv )
    int* argcP;
    char* argv[];
    {
    pgm_init( argcP, argv );
    }

void
ppm_nextimage(FILE *file, int * const eofP) {
    pm_nextimage(file, eofP);
}


void
ppm_readppminitrest( file, colsP, rowsP, maxvalP )
    FILE* file;
    int* colsP;
    int* rowsP;
    pixval* maxvalP;
    {
    int maxval;

    /* Read size. */
    *colsP = pbm_getint( file );
    *rowsP = pbm_getint( file );

    /* Read maxval. */
    maxval = pbm_getint( file );
    if ( maxval > PPM_OVERALLMAXVAL )
	pm_error("maxval (%d) is too large.\n"
             "The maximum allowed by the PPM is %d.",
             maxval, PPM_OVERALLMAXVAL); 
    *maxvalP = maxval;
    }


void
ppm_readppminit( file, colsP, rowsP, maxvalP, formatP )
    FILE* file;
    int* colsP;
    int* rowsP;
    int* formatP;
    pixval* maxvalP;
    {
    /* Check magic number. */
    *formatP = pm_readmagicnumber( file );
    switch ( PPM_FORMAT_TYPE(*formatP) )
	{
	case PPM_TYPE:
	ppm_readppminitrest( file, colsP, rowsP, maxvalP );
	break;

	case PGM_TYPE:
	pgm_readpgminitrest( file, colsP, rowsP, maxvalP );
	break;

	case PBM_TYPE:
	pbm_readpbminitrest( file, colsP, rowsP );
	*maxvalP = 1;
	break;

	default:
	pm_error( "bad magic number - not a ppm, pgm, or pbm file" );
	}
    }

#if __STDC__
void
ppm_readppmrow( FILE* file, pixel* pixelrow, int cols, pixval maxval, int format )
#else /*__STDC__*/
void
ppm_readppmrow( file, pixelrow, cols, maxval, format )
    FILE* file;
    pixel* pixelrow;
    int cols, format;
    pixval maxval;
#endif /*__STDC__*/
    {
    register int col;
    register pixel* pP;
    register pixval r, g, b;
    gray* grayrow;
    register gray* gP;
    bit* bitrow;
    register bit* bP;

    switch ( format )
	{
	case PPM_FORMAT:
        for ( col = 0, pP = pixelrow; col < cols; ++col, ++pP ) 
        {
            r = pbm_getint( file );
#ifdef DEBUG
            if ( r > maxval )
                pm_error( "r value out of bounds (%u > %u)", r, maxval );
#endif /*DEBUG*/
            g = pbm_getint( file );
#ifdef DEBUG
            if ( g > maxval )
                pm_error( "g value out of bounds (%u > %u)", g, maxval );
#endif /*DEBUG*/
            b = pbm_getint( file );
#ifdef DEBUG
            if ( b > maxval )
                pm_error( "b value out of bounds (%u > %u)", b, maxval );
#endif /*DEBUG*/
            PPM_ASSIGN( *pP, r, g, b );
	    }
	break;

	case RPPM_FORMAT:
	for ( col = 0; col < cols; ++col ) 
	    {
	    r = pgm_getrawsample( file, maxval );
#ifdef DEBUG
	    if ( r > maxval )
		pm_error( "r value out of bounds (%u > %u)", r, maxval );
#endif /*DEBUG*/
	    g = pgm_getrawsample( file, maxval );
#ifdef DEBUG
	    if ( g > maxval )
		pm_error( "g value out of bounds (%u > %u)", g, maxval );
#endif /*DEBUG*/
	    b = pgm_getrawsample( file, maxval );
#ifdef DEBUG
	    if ( b > maxval )
		pm_error( "b value out of bounds (%u > %u)", b, maxval );
#endif /*DEBUG*/
	    PPM_ASSIGN( pixelrow[col], r, g, b );
	    }
	break;

	case PGM_FORMAT:
	case RPGM_FORMAT:
	grayrow = pgm_allocrow( cols );
	pgm_readpgmrow( file, grayrow, cols, maxval, format );
	for ( col = 0, gP = grayrow, pP = pixelrow; col < cols; ++col, ++gP, ++pP )
	    {
	    r = *gP;
	    PPM_ASSIGN( *pP, r, r, r );
	    }
	pgm_freerow( grayrow );
	break;

	case PBM_FORMAT:
	case RPBM_FORMAT:
	bitrow = pbm_allocrow( cols );
	pbm_readpbmrow( file, bitrow, cols, format );
	for ( col = 0, bP = bitrow, pP = pixelrow; col < cols; ++col, ++bP, ++pP )
	    {
	    r = ( *bP == PBM_WHITE ) ? maxval : 0;
	    PPM_ASSIGN( *pP, r, r, r );
	    }
	pbm_freerow( bitrow );
	break;

	default:
	pm_error( "can't happen" );
	}
    }

pixel**
ppm_readppm( file, colsP, rowsP, maxvalP )
    FILE* file;
    int* colsP;
    int* rowsP;
    pixval* maxvalP;
    {
    pixel** pixels;
    int row;
    int format;

    ppm_readppminit( file, colsP, rowsP, maxvalP, &format );

    pixels = ppm_allocarray( *colsP, *rowsP );

    for ( row = 0; row < *rowsP; ++row )
	ppm_readppmrow( file, pixels[row], *colsP, *maxvalP, format );

    return pixels;
    }



void
ppm_check(FILE * file, const enum pm_check_type check_type, 
          const int format, const int cols, const int rows, const int maxval,
          enum pm_check_code * const retval_p) {

    if (check_type != PM_CHECK_BASIC) {
        if (retval_p) *retval_p = PM_CHECK_UNKNOWN_TYPE;
    } else if (PPM_FORMAT_TYPE(format) == PBM_TYPE) {
        pbm_check(file, check_type, format, cols, rows, retval_p);
    } else if (PPM_FORMAT_TYPE(format) == PGM_TYPE) {
        pgm_check(file, check_type, format, cols, rows, maxval, retval_p);
    } else if (format != RPPM_FORMAT) {
        if (retval_p) *retval_p = PM_CHECK_UNCHECKABLE;
    } else {        
        const unsigned int bytes_per_row =
            cols * 3 * (maxval > 255 ? 2 : 1);
        const unsigned int need_raster_size = rows * bytes_per_row;
        
        pm_check(file, check_type, need_raster_size, retval_p);
    }
}
